// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_BASE_CDM_CONTEXT_H_
#define MEDIA_BASE_CDM_CONTEXT_H_

#include "base/callback.h"
#include "base/macros.h"
#include "media/base/media_export.h"

namespace media {

class Decryptor;

// An interface representing the context that a media player needs from a
// content decryption module (CDM) to decrypt (and decode) encrypted buffers.
// This is used to pass the CDM to the media player (e.g. SetCdm()).
class MEDIA_EXPORT CdmContext {
public:
    // Indicates an invalid CDM ID. See GetCdmId() for details.
    static const int kInvalidCdmId;

    virtual ~CdmContext();

    // Gets the Decryptor object associated with the CDM. Returns nullptr if the
    // CDM does not support a Decryptor (i.e. platform-based CDMs where decryption
    // occurs implicitly along with decoding). The returned object is only
    // guaranteed to be valid during the CDM's lifetime.
    virtual Decryptor* GetDecryptor() = 0;

    // Returns an ID that can be used to find a remote CDM, in which case this CDM
    // serves as a proxy to the remote one. Returns kInvalidCdmId when remote CDM
    // is not supported (e.g. this CDM is a local CDM).
    virtual int GetCdmId() const = 0;

    // Returns a unique class identifier. Some subclasses override and use this
    // method to provide safe down-casting to their type.
    virtual void* GetClassIdentifier() const;

protected:
    CdmContext();

private:
    DISALLOW_COPY_AND_ASSIGN(CdmContext);
};

// Callback to notify that the CdmContext has been completely attached to
// the media pipeline. Parameter indicates whether the operation succeeded.
typedef base::Callback<void(bool)> CdmAttachedCB;

// A dummy implementation of CdmAttachedCB.
MEDIA_EXPORT void IgnoreCdmAttached(bool success);

} // namespace media

#endif // MEDIA_BASE_CDM_CONTEXT_H_
